Chapter 5

Given that Z is a standard normal random variable, P(-1.0 Z 1.5) is a. 0.7745 c. 0.0919 b. 0.8413 d. 0.9332

a. 0.7745

The standard deviation of a probability distribution is a: a. measure of variability of the distribution c. measure of relative likelihood b. measure of central location d. measure of skewness of the distribution

a. measure of variability of the distribution

One reason for standardizing random variables is to measure variables with: a. different means and standard deviations on a non-standard scale b. different means and standard deviations on a single scale c. dissimilar means and standard deviations in like terms d. similar means and standard deviations on two scales

b. different means and standard deviations on a single scale

The mean of a probability distribution is a: a. measure of variability of the distribution c. measure of relative likelihood b. measure of central location d. measure of skewness of the distribution

b. measure of central location

The higher the value of the density function f(x), a. the less likely the value x c. the less likely the distribution is normal b. the more likely the value x d. None of the above

b. the more likely the value x

Given that Z is a standard normal variable, the value z for which P(Z z) = 0.2580 is a. 0.70 c. -0.65 b. 0.758 d. 0.242

c. -0.65

If we plot a continuous probability distribution f(x), the total probability under the curve is a. -1 c. 1 b. 0 d. 100

c. 1

If the value of the standard normal random variable Z is positive, then the original score is where in relationship to the mean? a. equal to the mean c. to the right of the mean b. to the left of the mean d. None of the above

c. to the right of the mean

The standard normal distribution has a mean and a standard deviation respectively equal to a. 0 and 0 c. 1 and 0 b. 1 and 1 d. 0 and 1

d. 0 and 1

Given that the random variable X is normally distributed with a mean of 80 and a standard deviation of 10, P(85 X 90) is a. 0.5328 c. 0.1915 b. 0.3413 d. 0.1498

d. 0.1498

The normal distribution is: a. a discrete distribution with two parameters b. a binomial distribution with only one parameter c. a density function of a discrete random variable d. a continuous distribution with two parameters

d. a continuous distribution with two parameters

Which of the following equations shows the process of standardizing? a. c. b. d.

z=(X-u)/o